Analytical methods in use in clinical laboratories have been evaluated. New methods and instrumentaton have been studied and effects of drugs on test values determined. Continued work with automatic interpretation of effects of drugs has shown that it is possible to assist physicians in understanding influence of drug therapy in changing laboratory test values. BIBLIOGRAPHIC REFERENCES: Forman, D.T. and Young, D.S. Drug interference in laboratory testing. An. Clin. Lab. Sci. 6, 263-271, 1976. McClean, S.W., Young, D.S. and Yonekawa, W. Anticonvulsants in serum, determined with a fully mechanized enzyme analyzer. Clin. Chem. 23, 116-118, 1977.